Roller skates



1951 E. KARDHORDO 4 ROLLER SKATES Filed Dec. 10, 1947 2 Sheets-Sheet l Eugen KuwclM1-&o

Oct. 9, 1951 E. KARDHORDO ROLLER SKATES 2 Sheets-Sheet 2 Filed Dec. 10, 1947 Lflanlm-z Eng an KMQLMM Patented Oct. 9, I951 UNITED STATES PATENTIIOFFICE ROLLER SKATES Eugen Kardhordo, Bratislava, Czechoslovakia, assignor of one-half to Sigma Pumps, National Corporation, Olomouc, Czechoslovakia Application December 10, 1947, Serial No. 790,847

In Czechoslovakia January 10, 1947 My invention relatesto roller skates and more particularly to roller skates suitable for roller skating in which at least three rollers orwheels are arranged in tandem formation.

The main object of this invention is to provide an improved roller-skate of the said type which will allow quick starts and sudden stops with out impairing a safe support for the user of the skate, and which will permit to attain high speed even in quick and sharp turns.

According to my invention my improved roller skate comprises at least two auxiliary rollers and an intermediary main roller arranged in a single track the convex running surface of all rollers,

when read with the accompanying drawing in.

which Fig. 1 is a plan view of my improved roller skate taken from underneath and showing a skate containing three rollers or wheels arranged in alignment,

Fig. 2 is an elevational view to Fig. l'partly in section,

Fig. 3 illustrates diagrammatically cross section of the rollers in planes passing through their 1 axis of rotation while the plane of rotation of said rollers is perpendicular to the racing surface;

Fig. 4, which corresponds to Fig. 3, showsa different inclination of the plane of rotation of the rollers in respect to the racing surface, Fig. 5 is a section on the line 5-5 in Fig. 2, Fig. 6 is a similar section of another embodiment,

- Fig. 7 is a side view showing the rear part of and Figs. 8 and 9 show in cross section-and in partial side view, respectively, still another embodiment of the rollers used in my improve skates. r

As shown in Figs. 1, 2, 5, the frame I of the skate is provided with suitable foot plates 2, 3. Three rollers or wheels 4, 5, 6 are mounted pref-' erablyupon ball bearings in the frame I behind each other in the direction of racing. Said rollers are of different size and have differently shapedv running surfaces clearly appearing from' a roller skate in the embodiment shown in Fig. 6,

" 3 Claims. ((1280-1122) K .Fig. 1 and schematically shown in Figs. 3 and 4;.

wherein IV indicates the running surface of" roller 4, V the running surface of roller 5 and VI that of roller 6. Under a certain angle of inclination (,0 of the plane of rotation S-S in respect to the racing surface P (in Fig. 3 at an angle- =90) the running surface IV, V, VI of all rollers 4, 5, 6 contact the course surface P. With increasing angle (p the differently shaped running surfaces IV and VI of the auxiliary rollers 4 and 6 will one by one disengage from the racing surface P until only the surface V of main roller 5 remains in contact with the racing surface P. In the shown embodiment the main roller 5 has the largest diameter and its running surface V has a spherical shape.

As shown in Fig. 5 the main roller 5 which.

. preferably is made from a light metal is mounted.

in the frame I by means of a bolt 8 and two ball. bearings 9. The surface of said roller 5 is coated. with a lining I of a suitable elastic and suffi-- ciently hard and rough material, such as rubber.. The rear auxiliary roller 6 is also sphericallyshaped but has a smaller diameter than the roller 5. The front auxiliary roller 4 has the: shape of a narrow wheel with an elastic tire. At. the front end of the adequately stiifened frame: I a suitable jump 01f abutment I1 is provided in; the shape of a screwed-in plug made of rubber: or similar material.

Fig. 6 shows a somewhat modified arrangetherein by suitable attachment rings. Said ball.

bearing supports the complementary halves 1.. II of the roller which parts are connected by a bolt l3. The web 14 extends rearwards in a braking spur l6 as shown in Fig. 7.

When racing in a straight direction the plane of rotation S--S of the rollers 4, 5, 6 is'approximately perpendicular to the racing surface as indicated in Fig; 3 and all three rollers 4, 5, 6

contact with their running surfaces IV, V, VI

the racing course P tending to guide the skate in a straight direction. The skate resting with all three rollers upon the race course has a considerable stability, as there is no possibility of easy tipping forwards or rearwards. If, however. the skate is inclined laterally, into the position shown inFig'. 4, only the main roller (running surface V) remains finally engaged with the course surgaged therefrom? The entire load is then resting on the main roller 5 of spherical shape which offers to any change of the racing direction a far smaller resistance than a set of two or more rollers arranged behind each other and uniformly loaded. Therefore the disclosed arrangement according to the invention allows racing in curves of even small radius simply by a rolling movement of the main roller eliminating any skidding and undesirable friction of the auxilriary rollers. An almost ideal rolling motion in curves results from the rolling body 5 running: on the course P with only a narrow contacting strip of the width 10. r I I 1 It is to be understood thatitis not'tin-di'spens= able that in curve racing only'the main roller 5 contacts the race course P; It; may be; admise sible and even desirable in view of improving: the. stability that some of the auxiliary rollersv 4 or 6 transiently contact thecourse surface. However, it is essential that aprevailing part of the load rests onthe main roller 5; This require mentis fulfilled if themain roller 5 is" arranged between the auxiliary'roll'ers land 6-.

The spherical shape of' the running surface V of themain roller is particularly suitablebecause it guarantees a" permanently uniform en'- gagement with the racing course surface P at any angleof' inclination o" and a maximum stability in transverse direction. The-basic idea of thepresent invention may, however; be carried" intoeife'ct' with other suitable'shapesof the main roller- 5; if only the selected shape matches the profiles of the auxiliary rollers. 44" and 6" in such manner-that the said, auxiliary bodies 4'; 6. are. at certain inclinations of the'plane'SSi'of rotation lifted out of. engagement. with thecourse surface P. Preferablythe main roller {alfhas the largest diameter din order to reduce to a minimum the losses duringthe race upon this utmost loaded body;

' The jump-off abutment Hthroughits engage.- ment'. with the. course surface P facilitates the. jumping on and thereby also sudden, turns. and. high racing speeds. By means ofjthe braking. spur [61' (Fig. 7) efiicientbrakingmay be per.- formed through its engagementiinto the racing. course which isof special importance when.p1aying hockey. The constructional. embodiment. shown in Fig. 6- involving a two-partrolling, body H3, H and a central weld llllfacilitatesga very simple arrangement of the. braking spur [6. which may also be providedwithaprojectioh. like the jump-off abutment II. It. is. to. be. understood that instead of two auxiliary rollers, a greater number of'such rollers may be pro,-= vided thus attaining the advantage. of, better;- overcoming any unevennesses ofthe course.

In Fig. 8 which shows still, another embodi.- ment of the present invention, 24 is the frame of a roller skate wherein by means of apivot .23. and ball bearings 22 a metallic roller 21' is. ro-

tatably supported, saidroller 2| being provided with a rubber lining 25.. At both sides of. said roller 2| border discs 26 of a hardsteel plate. with a sharp outer edge 2 are attached thereto. by rivets 28, said edge 2.! being. approximately at the same level asthe. surface of the-rubber lining. 25.

In normal straight. racing. the skateruns on. the course with its elasticlining-ZS and-the edges; 2'l.are ineffective. Only when the central-plane; of. the. skate inclinestowards the: course to a". suificient. extentthe sharp edge-21 ;=comes.- into;

of the fact that the material whereof the disc 26 is made is very hard, a very efficient engagement is thus attained Without any risk of damaging the edge 21. The roller according to the .present invention which may also be of any other suitable profile than that illustrated thus combines in itself the necessary features ensuring an elastical racing, as Well as the possibility of an efiective engagement for jumping off and braking, and an outstanding durability.

Inthe embodiment shown in Fig. 9 the roller 3| is laterally provided with hard discs 29 having a circumferential teething 30 to enable a still sharper-engagement;

It is also possible to provide instead of sharp edgesblunt rims or even rounded off rims with a: roughened surface. The nature and hardness of the course is decisive for the choice of the respective design. Likewise the connection between the rims and the remaining portions of the roller may be performed in any suitable manner and theborderdiscs may be'exchangeable'. It is t'obe noted, however, that the material of the rims is to be harder than the material of the-running-surface of the rollers.

some of therollers, preferably the foremost, may also be provided with aone-way free motion preventing any backward rotation so that the respective roller maybe used as a jump off.

The roller skates according to-this'invention are; asfar as speediness, possibility of racing in sharp curves, safety of control and fitness for figure-skating, and hockey competitions is concerned, fully equivalent to edge-skates which are suitableonly for ice courses.

While specific. embodiments of my invention have beenshown and described in detail to illustrate'the application of the principles of my invention, it will. be understood'that the same may be otherwise embodied without departing. from suchprinciples.

What Iclaim as my invention is:

1; In.a...roller skate the improvement comprising in combination a' supporting'frame, at least two auxiliary rollers and anintermediate main roller in. tandem formation, fixedaxles for said rollers mountedin said frame, each ofsaidrollers having a transverse convex running surface contacting .,the supporting surface while. the rollers rotate in a plane essentially perpendicular to the supporting surface, the convex running surface of the. main .rollerhaving a greater radius of curvaturethan the running surfaces of the. auxiliary rollers.

2...In .a roller skate. the improvement comprising in combination a supporting frame, at least two auxiliary. rollers and an intermediate main roller in tandem'formation, fixed axles for said rollers "mounted in saidframe, each of said rollers having a transverse convex running surface contacting the supporting surface whilethe rollers rotatein a plane essentially perpendicular to the supporting surface, the convex running sur faces oftherollers having difierentradii of curvature thei running surface of the. main roller beingv two auxiliary rollers and: an: iintermediatez'maint roller; in :tandem. .formation; fixed 'axles for said rollers mounted in :said framepeach :Ofnsaid roll-eersmaving; aitransverse convex1- running surface 1 and: at least the .main: roller aysphericallyzshapedi engagement with the co11rse-sur.-face.:. In; view. 75-.r nnin s rfa e the; running.=. surfaces: of: all;-

three rollers contacting the supporting surface while the rollers rotate in a plane essentially perpendioular to the supporting surface, the spherically shaped running surface of the main roller having a greater radius of curvature than the running surfaces of the auxiliary rollers.

EUGEN KARDHORDO.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Number Name Date Duisenberg Oct. 21, 1930 Siffert Apr. 12, 1938 Burton Jan. 24, 1939 FOREIGN PATENTS Country Date Great Britain Aug. 13, 1908 Switzerland Jan. 2, 1935 Switzerland Mar. 1, 193? 

